chore: import upstream snapshot with attribution

tests/unittests/agents/test_loop_agent.py

@@ -0,0 +1,292 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Testings for the SequentialAgent."""
+
+from typing import AsyncGenerator
+from unittest.mock import patch
+
+from google.adk.agents.base_agent import BaseAgent
+from google.adk.agents.invocation_context import InvocationContext
+from google.adk.agents.loop_agent import LoopAgent
+from google.adk.agents.loop_agent import LoopAgentState
+from google.adk.apps import ResumabilityConfig
+from google.adk.events.event import Event
+from google.adk.events.event_actions import EventActions
+from google.adk.sessions.in_memory_session_service import InMemorySessionService
+from google.genai import types
+import pytest
+from typing_extensions import override
+
+from .. import testing_utils
+
+END_OF_AGENT = testing_utils.END_OF_AGENT
+
+
+class _TestingAgent(BaseAgent):
+
+  @override
+  async def _run_async_impl(
+      self, ctx: InvocationContext
+  ) -> AsyncGenerator[Event, None]:
+    yield Event(
+        author=self.name,
+        invocation_id=ctx.invocation_id,
+        content=types.Content(
+            parts=[types.Part(text=f'Hello, async {self.name}!')]
+        ),
+    )
+
+  @override
+  async def _run_live_impl(
+      self, ctx: InvocationContext
+  ) -> AsyncGenerator[Event, None]:
+    yield Event(
+        author=self.name,
+        invocation_id=ctx.invocation_id,
+        content=types.Content(
+            parts=[types.Part(text=f'Hello, live {self.name}!')]
+        ),
+    )
+
+
+class _TestingAgentWithEscalateAction(BaseAgent):
+
+  @override
+  async def _run_async_impl(
+      self, ctx: InvocationContext
+  ) -> AsyncGenerator[Event, None]:
+    yield Event(
+        author=self.name,
+        invocation_id=ctx.invocation_id,
+        content=types.Content(
+            parts=[types.Part(text=f'Hello, async {self.name}!')]
+        ),
+        actions=EventActions(escalate=True),
+    )
+    yield Event(
+        author=self.name,
+        invocation_id=ctx.invocation_id,
+        content=types.Content(
+            parts=[types.Part(text='I have done my job after escalation!!')]
+        ),
+    )
+
+
+async def _create_parent_invocation_context(
+    test_name: str, agent: BaseAgent, resumable: bool = False
+) -> InvocationContext:
+  session_service = InMemorySessionService()
+  session = await session_service.create_session(
+      app_name='test_app', user_id='test_user'
+  )
+  return InvocationContext(
+      invocation_id=f'{test_name}_invocation_id',
+      agent=agent,
+      session=session,
+      session_service=session_service,
+      resumability_config=ResumabilityConfig(is_resumable=resumable),
+  )
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize('resumable', [True, False])
+async def test_run_async(request: pytest.FixtureRequest, resumable: bool):
+  agent = _TestingAgent(name=f'{request.function.__name__}_test_agent')
+  loop_agent = LoopAgent(
+      name=f'{request.function.__name__}_test_loop_agent',
+      max_iterations=2,
+      sub_agents=[
+          agent,
+      ],
+  )
+  parent_ctx = await _create_parent_invocation_context(
+      request.function.__name__, loop_agent, resumable=resumable
+  )
+  events = [e async for e in loop_agent.run_async(parent_ctx)]
+
+  simplified_events = testing_utils.simplify_resumable_app_events(events)
+  if resumable:
+    expected_events = [
+        (
+            loop_agent.name,
+            {'current_sub_agent': agent.name, 'times_looped': 0},
+        ),
+        (agent.name, f'Hello, async {agent.name}!'),
+        (
+            loop_agent.name,
+            {'current_sub_agent': agent.name, 'times_looped': 1},
+        ),
+        (agent.name, f'Hello, async {agent.name}!'),
+        (loop_agent.name, END_OF_AGENT),
+    ]
+  else:
+    expected_events = [
+        (agent.name, f'Hello, async {agent.name}!'),
+        (agent.name, f'Hello, async {agent.name}!'),
+    ]
+  assert simplified_events == expected_events
+
+
+@pytest.mark.asyncio
+async def test_resume_async(request: pytest.FixtureRequest):
+  agent_1 = _TestingAgent(name=f'{request.function.__name__}_test_agent_1')
+  agent_2 = _TestingAgent(name=f'{request.function.__name__}_test_agent_2')
+  loop_agent = LoopAgent(
+      name=f'{request.function.__name__}_test_loop_agent',
+      max_iterations=2,
+      sub_agents=[
+          agent_1,
+          agent_2,
+      ],
+  )
+  parent_ctx = await _create_parent_invocation_context(
+      request.function.__name__, loop_agent, resumable=True
+  )
+  parent_ctx.agent_states[loop_agent.name] = LoopAgentState(
+      current_sub_agent=agent_2.name, times_looped=1
+  ).model_dump(mode='json')
+
+  events = [e async for e in loop_agent.run_async(parent_ctx)]
+
+  simplified_events = testing_utils.simplify_resumable_app_events(events)
+  expected_events = [
+      (agent_2.name, f'Hello, async {agent_2.name}!'),
+      (loop_agent.name, END_OF_AGENT),
+  ]
+  assert simplified_events == expected_events
+
+
+@pytest.mark.asyncio
+async def test_run_async_skip_if_no_sub_agent(request: pytest.FixtureRequest):
+  loop_agent = LoopAgent(
+      name=f'{request.function.__name__}_test_loop_agent',
+      max_iterations=2,
+      sub_agents=[],
+  )
+  parent_ctx = await _create_parent_invocation_context(
+      request.function.__name__, loop_agent
+  )
+  events = [e async for e in loop_agent.run_async(parent_ctx)]
+  assert not events
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize('resumable', [True, False])
+async def test_run_async_with_escalate_action(
+    request: pytest.FixtureRequest, resumable: bool
+):
+  non_escalating_agent = _TestingAgent(
+      name=f'{request.function.__name__}_test_non_escalating_agent'
+  )
+  escalating_agent = _TestingAgentWithEscalateAction(
+      name=f'{request.function.__name__}_test_escalating_agent'
+  )
+  ignored_agent = _TestingAgent(
+      name=f'{request.function.__name__}_test_ignored_agent'
+  )
+  loop_agent = LoopAgent(
+      name=f'{request.function.__name__}_test_loop_agent',
+      sub_agents=[non_escalating_agent, escalating_agent, ignored_agent],
+  )
+  parent_ctx = await _create_parent_invocation_context(
+      request.function.__name__, loop_agent, resumable=resumable
+  )
+  events = [e async for e in loop_agent.run_async(parent_ctx)]
+
+  simplified_events = testing_utils.simplify_resumable_app_events(events)
+
+  if resumable:
+    expected_events = [
+        (
+            loop_agent.name,
+            {
+                'current_sub_agent': non_escalating_agent.name,
+                'times_looped': 0,
+            },
+        ),
+        (
+            non_escalating_agent.name,
+            f'Hello, async {non_escalating_agent.name}!',
+        ),
+        (
+            loop_agent.name,
+            {'current_sub_agent': escalating_agent.name, 'times_looped': 0},
+        ),
+        (
+            escalating_agent.name,
+            f'Hello, async {escalating_agent.name}!',
+        ),
+        (
+            escalating_agent.name,
+            'I have done my job after escalation!!',
+        ),
+        (loop_agent.name, END_OF_AGENT),
+    ]
+  else:
+    expected_events = [
+        (
+            non_escalating_agent.name,
+            f'Hello, async {non_escalating_agent.name}!',
+        ),
+        (
+            escalating_agent.name,
+            f'Hello, async {escalating_agent.name}!',
+        ),
+        (
+            escalating_agent.name,
+            'I have done my job after escalation!!',
+        ),
+    ]
+  assert simplified_events == expected_events
+
+
+@pytest.mark.asyncio
+async def test_run_async_with_pause_preserves_sub_agent_state(
+    request: pytest.FixtureRequest,
+):
+  """Test that the sub-agent state is preserved when the loop agent pauses."""
+  agent = _TestingAgent(name=f'{request.function.__name__}_test_agent')
+  loop_agent = LoopAgent(
+      name=f'{request.function.__name__}_test_loop_agent',
+      max_iterations=2,
+      sub_agents=[agent],
+  )
+  parent_ctx = await _create_parent_invocation_context(
+      request.function.__name__, loop_agent, resumable=True
+  )
+
+  # Set some dummy state for the sub-agent
+  parent_ctx.agent_states[agent.name] = {'some_key': 'some_value'}
+
+  # Mock should_pause_invocation to return True for the agent's event
+  def mock_should_pause(event):
+    return event.author == agent.name
+
+  with patch.object(
+      InvocationContext,
+      'should_pause_invocation',
+      side_effect=mock_should_pause,
+  ):
+    async for _ in loop_agent.run_async(parent_ctx):
+      pass  # Consume the async generator
+
+  # Verify that the sub-agent state was NOT reset
+  assert agent.name in parent_ctx.agent_states
+  assert parent_ctx.agent_states[agent.name] == {'some_key': 'some_value'}
+
+
+def test_deprecation_mentions_sub_agent_limitation():
+  with pytest.warns(DeprecationWarning, match='sub-agent'):
+    LoopAgent(name='deprecated_loop', sub_agents=[])